Over the course of nearly four full seasons, ‘Walking Dead’ has used a wide range of music from artists that span nearly every genre and era including Bob Dylan, Motörhead, the Stanley Brothers, Sharon Van Etten, Wang Chung and Tom Waits, whose song “Hold On” was sung by cast member Emily Kinney. For the remainder of the show’s fourth season, we’ll be talking with Thomas Golubic of SuperMusicVision, who helps choose the show’s music, to get the scoop on what you heard last night.

We don’t know much about Bob Stookey (played by Lawrence Gilliard Jr.) other than he used to be a medic, and that he has struggled with a drinking problem. On this week’s episode (March 9), titled “Alone,” we saw a bit of his past with flashback sequences of his time alone on the road, before getting picked up by Daryl (Norman Reedus) and Glenn (Steven Yeun). In the present, he explains to Sasha (Sonequa Martin-Green) that he’d been the last member standing of two other groups, post-apocalypse. She asks why he’s happy: it’s because he simply is happy being with other people, as opposed to being by himself. The flashback was soundtracked by “Blackbird Song,” by “American Idol” season nine winner Lee DeWyze.

The lyrics, “Pack your things, leave somehow” seemed to also speak to Sasha, who, unlike Bob and their other traveling companion Maggie (Lauren Cohan), does not want to travel to “Terminus,” where safety and community are promised (albeit by some kind of ominous looking signs). She’d prefer to find a high building, and stay there, safe from the walkers. It’s going to be a long road to Terminus.

It’s also a long way from “American Idol” to “Walking Dead”; so how did Lee DeWyze’s song end up on the show?

“‘Blackbird Song’ first arrived with a very kind e-mail from Fred Jasper of Welk Music Group,” Golubic tells Radio.com, refering to the parent company of Vanguard Records, the label that DeWyze is signed to. “Fred was commenting on an interview I had done about the end of ‘Breaking Bad’ [Golubic supervised that show’s music as well] and passed along a download link from Lee DeWyze, mentioning how big a fan Lee was of ‘The Walking Dead’ and that he wrote ‘Blackbird Song’ with ‘The Walking Dead’ in mind. Maybe it was the nice words or the time of day, but as soon as I listened to the song it became clear that this was in ‘The Walking Dead’s wheelhouse and something show-runner Scott Gimple should hear. Scott responded very positively to the song and when it came time to telling Bob Stookey’s back story, ‘Blackbird Song’ turned out to be a fantastic structure to build the opening and closing of the episode.”

“‘Blackbird Song’ captures that sense of loneliness and helps us understand why Bob strives to find a community, even under the most desperate of circumstances. The song bookends Bob’s story in this episode, essentially making it his theme, similar to how Ben Howard’s ‘Oats In The Water’ became Hershel’s theme in episode 405.”

The other musical moment in the episode came when Beth Greene (Emily Kinney) sang “Be Good,” by the indie folk band Waxahatchee, led by Katie Crutchfield. Beth and Daryl found safety in a remarkably well-kept but seemingly abandoned funeral home, which happened to have a piano in it. She sat down and started singing “Be Good,” which includes the lyric “You don’t want to be my boyfriend and I don’t want to be your girl,” seemingly answering the fans wondering if there will be any sparks flying between the traveling companions, who bonded over some moonshine and dead walkers in last week’s episode. Apologies for the spoiler, but events out of their control would have kept that from happening, at least in the immediate future.

With all due respect to Waxahatchee, “Be Good” wasn’t what Beth was originally supposed to sing. Golubic tells us, “A Neutral Milk Hotel song had been scripted into this episode, but because of a licensing hurdle we landed on ‘Be Good’ as an alternate choice.” And even though “Be Good” comes from the band’s 2012 album American Weekend, which was released months after the debut of “Walking Dead” in our reality (in October 2010), don’t let that bother you! Creative license!

Greene has sung a few times over the course of the series (Tom Waits’ “Hold On” and “I Don’t Wanna Grow Up”) – which makes sense, as in real life, Kinney is a musician who’s putting out her second EP, Expired Love, on March 18. Her singing is not exactly the Greek chorus of “The Walking Dead,” but it’s used at specific points in the story.

Golubic says, “Each time Beth sings, it takes a temporary shelter and turns it into a home. It’s the equivalent of putting flowers into a vase. We first heard her sing at the campfire, then inside the prison, and now inside this funeral home. For Daryl, it’s nothing more than a temporary shelter. As Beth tries to convince Daryl that there is still good in the world, the Waxahatchee song speaks on her behalf.” And, of course, (spoiler alert again), events soon proved that the good people are extremely difficult to find.

Season 4 has three weeks left: check back with us next week after episode 14, “The Grove,” to find out what music they chose, and why they chose it.